OFFSET
0,2
REFERENCES
S. R. Finch, Mathematical Constants, Cambridge, 2003, Section 1.6.3.
LINKS
Index entries for linear recurrences with constant coefficients, signature (4, -6, 4, -1).
FORMULA
Sum_{n>=0} 1/a(n) = Pi^3/64 + 7 zeta(3)/16.
a(0)=1, a(1)=125, a(2)=729, a(3)=2197, a(n)=4*a(n-1)-6*a(n-2)+ 4*a(n-3)- a(n-4). - Harvey P. Dale, Sep 01 2013
G.f.: ( 1+121*x+235*x^2+27*x^3 ) / (x-1)^4 . - R. J. Mathar, Dec 03 2015
MATHEMATICA
(4*Range[0, 30]+1)^3 (* or *) LinearRecurrence[{4, -6, 4, -1}, {1, 125, 729, 2197}, 30] (* Harvey P. Dale, Sep 01 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved